The problem of generating reliable, accurate printed output on a printer or other output device has occupied application programmers, operating system designers, printer and other hardware engineers and others for some time. In general, printed, facsimile or other output has been subject to inconsistencies such as misaligned pages, improperly formed characters or fonts, limited or poorly executed effects such as shadowing or keming, or other problems due to the technical issues surrounding the printing chain.
For one, and as illustrated in FIG. 1, generating a printed page or other output typically begins with an application such as a word processing package, presentation package, spreadsheet or other application generating a document, slide show, spreadsheet or other file, object or data to send to a printer or other output device.
The application usually accesses an application programming interface (API) in the operating system to transmit that file to the operating system for output spooling and processing. The application may be required to conform to the API for instance by passing constituent text, numerical, graphical or other data as well as arguments and variables related to the resolution, font, page size and other characteristics of the output file. The API may then invoke other resources of the operating system to serialize or spool the file for transmission to the printer or other output device.
The operating system may communicate the spooled file or other data to a printer driver, for example a software interpreter or commands and functions, resident in the operating system or supplied by the hardware manufacturer. The printer driver may then transmit the resulting processed output data to the printer hardware via a serial, parallel or other connection. The printer or other output device may then process the received document or other object to generate a printed page, for instance using a print engine containing routines, fonts, logic control and other information which is embedded in the printer.
The series of conventional processing and conversion steps which translate an original source file to a form for ultimate printing introduces multiple chances for errors and incompatibilities between source data and physical output. For one thing, not all applications are aware of the font, effects and other processing limitations of given printers or other output devices. For another, the APIs presented to applications may be hardwired to specifications which do not permit substitution or extension of fonts or other effects or processing. Moreover, interposing a manufacturer-specific printer driver or other driver between the operating system and output device only increases the possibility of incompatible fonts, routines or commands. Other problems in printing and other output technology exist.